java - selenium cucumber JUnit 框架中的空指针异常

Question

有人可以告诉我代码中的空指针异常问题吗？

控制台中的错误消息

  =>test.pages.HomePage@31e75d13<=

    [31mFailed scenarios:[0m
    [31mE2E_Test.feature:3 [0m# Scenario: Test scenario

    1 Scenarios ([31m1 failed[0m)
    10 Steps ([31m1 failed[0m, [36m8 skipped[0m, [32m1 passed[0m)
    0m12.461s

    java.lang.NullPointerException
        at org.openqa.selenium.support.pagefactory.DefaultElementLocator.findElement(DefaultElementLocator.java:69)
        at org.openqa.selenium.support.pagefactory.internal.LocatingElementHandler.invoke(LocatingElementHandler.java:38)
        at com.sun.proxy.$Proxy17.sendKeys(Unknown Source)
        at test.pages.HomePage.enterSearchText(HomePage.java:31)
        at stepDefinitions.Steps.he_search_for(Steps.java:49)
        at ✽.When he search for "test"(E2E_Test.feature:5)

虽然我正在获取驱动程序对象，并且它也不是 Null，但仍然遇到 空指针异常。

我正在尝试运行selenium webdriver代码来自动化一些测试用例。在这里，我尝试打开 google.com 并希望在搜索框中输入一些文本，但打开 google.com 后，当执行到达 searchtextbox.sendkeys("test")，它给出了空指针异常。我尝试调试它以查看主页类对象是否为 null，但它显示的是值而不是 null。

这是我用来启动 Google 网站并最大化代码的测试基类

public class TestBase {

  public static WebDriver driver;
  public static Properties prop;
  public static EventFiringWebDriver e_driver;
  public static WebEventListener eventListener;

  public TestBase() {
    try {
      prop = new Properties();

      FileInputStream ip = new FileInputStream(System.getProperty("user.dir") + "/src/main/java/test" +
        "/config/config.properties");
      prop.load(ip);
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

  // This method is used to initiatize the site url

  public static void initialization(String url) {
    String browserName = prop.getProperty("browser");

    if (browserName.equals("chrome")) {
      System.setProperty("webdriver.chrome.driver", "C:\\Users\\test\\Downloads\\driver\\chromedriver.exe");
      driver = new ChromeDriver();
    }



    e_driver = new EventFiringWebDriver(driver);
    // Now create object of EventListerHandler to register it with EventFiringWebDriver
    eventListener = new WebEventListener();
    e_driver.register(eventListener);
    driver = e_driver;

    driver.manage().window().maximize();
    driver.manage().deleteAllCookies();
    driver.manage().timeouts().pageLoadTimeout(TestUtil.PAGE_LOAD_TIMEOUT, TimeUnit.SECONDS);
    driver.manage().timeouts().implicitlyWait(TestUtil.IMPLICIT_WAIT, TimeUnit.SECONDS);
    if (url == "google") {
      driver.get(prop.getProperty("url"));
    }

  }
}

//    Steps Definition file (Steps.java):    This is the step defintion file // there is a function he_search_for called where the exception occurs

public class Steps extends TestBase {

  WebDriver driver;
  TestUtil testUtil;

  HomePage homePage;

  @Given("^user is on google home page$")
  public void user_is_on_google_home_page() throws Throwable {
    initialization("google");
    testUtil = new TestUtil();
    homePage = new HomePage(driver);
  }

  @When("^he search for \"([^\"]*)\"$")
  public void he_search_for(String arg1) throws InterruptedException {
    System.out.print("=>" + homePage + "<=");
    homePage.enterSearchText();
  }
}

//    HomePage Class is used to define all the page elements here in this class, i used enterSearchText function to enter the text in a search box. 

public class HomePage extends TestBase {

  @FindBy(name = "q")
  WebElement searchTextBox;


  WebDriver driver;

  // Initializing the Page Objects:
  public HomePage(WebDriver driver) {
    this.driver = driver;
    PageFactory.initElements(driver, this);
  }

  public void enterSearchText() {
    searchTextBox.sendKeys("Test");
  }
}

Answer 1

问题出在类步骤和测试库之间的代码设计模式中。请注意

首先，类Steps正在扩展TestBase，其中已经声明并初始化了WebDriver变量。因此您不需要在步骤中再次定义WebDriver实例。所以请删除“WebDriver 驱动程序；”从下面的代码和平。

public class Steps extends TestBase {

  WebDriver driver;
  TestUtil testUtil;

第二，请不要将WebDriver声明为静态变量。请将其声明为非静态，因为保持静态也可能在并行执行期间产生问题。

public class TestBase {

  public  WebDriver driver; 

将 WebDriver 实例设为非静态并使其线程安全

TestBase.java

public class TestBase {

    public WebDriver driver;
    public static Properties prop;

    // This method is used to initiatize the site url
    public synchronized void initialization(String url) {
        String browserName = prop.getProperty("browser");
        if (browserName.equals("chrome")) {
            System.setProperty("webdriver.chrome.driver", "C:\\Users\\test\\Downloads\\driver\\chromedriver.exe");
            driver = new ChromeDriver();
            DriverManager.setWebDriver(driver);
        }
    }
}

DriverManager.java

import org.openqa.selenium.WebDriver;
public class DriverManager {

public static ThreadLocal<WebDriver> dr = new ThreadLocal<WebDriver>();

public static WebDriver getDriver() {
    return dr.get();
}

public static void setWebDriver(WebDriver driver) {
    dr.set(driver);
}
}